U.S. patent application number 16/373980 was filed with the patent office on 2020-06-11 for separator assembly for fuel cell and fuel cell stack including same.
The applicant listed for this patent is Hyundai Motor Company Kia Motors Corporation. Invention is credited to Seong Il Heo, Byeong-Heon Jeong, Yoo Chang Yang.
Application Number | 20200185730 16/373980 |
Document ID | / |
Family ID | 70776562 |
Filed Date | 2020-06-11 |
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United States Patent
Application |
20200185730 |
Kind Code |
A1 |
Heo; Seong Il ; et
al. |
June 11, 2020 |
SEPARATOR ASSEMBLY FOR FUEL CELL AND FUEL CELL STACK INCLUDING
SAME
Abstract
A separator assembly for a fuel cell includes: a first separator
having a protruding bead seal providing a seal; a second separator
joined to the first separator to be integrated therewith and having
an arched bulge protruding in the same direction as the bead seal
at a location corresponding to a location where the bead seal is
formed; a gasket provided on a concave surface of the bulge of the
second separator at the location where the bulge is formed, the
concave surface being opposite to a convex surface of the bulge;
and a sealing agent applied to a convex surface of the bead seal of
the first separator at the location where the bead seal is
formed.
Inventors: |
Heo; Seong Il; (Yongin,
KR) ; Yang; Yoo Chang; (Gunpo, KR) ; Jeong;
Byeong-Heon; (Yongin, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company
Kia Motors Corporation |
Seoul
Seoul |
|
KR
KR |
|
|
Family ID: |
70776562 |
Appl. No.: |
16/373980 |
Filed: |
April 3, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 8/0247 20130101;
H01M 8/0276 20130101 |
International
Class: |
H01M 8/0247 20060101
H01M008/0247; H01M 8/0276 20060101 H01M008/0276 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2018 |
KR |
10-2018-0156386 |
Claims
1. A separator assembly for a fuel cell, the separator assembly
comprising: a first separator having a protruding bead seal
providing a seal; a second separator joined to the first separator
to be integrated therewith and having an arched bulge protruding in
the same direction as the bead seal at a location corresponding to
a location where the bead seal is formed; a gasket provided on a
concave surface of the bulge of the second separator at the
location where the bulge is formed, the concave surface being
opposite to a convex surface of the bulge; and a sealing agent
applied to a convex surface of the bead seal of the first separator
at the location where the bead seal is formed.
2. The separator assembly of claim 1, wherein the bulge formed at
the second separator is lower in protruding height than the bead
seal formed at the first separator.
3. The separator assembly of claim 2, wherein a height of the bulge
formed at the second separator is equal to or less than the sum of
thicknesses of the first separator and the second separator.
4. The separator assembly of claim 1, wherein the gasket is larger
in width than the sealing agent.
5. The separator assembly of claim 1, wherein the gasket is formed
by injecting an elastic rubber material, and the sealing agent is
applied by screen coating.
6. A fuel cell stack formed by stacking multiple unit cells, the
fuel cell stack comprising: the multiple unit cells each comprised
of a membrane electrode assembly having a sub-gasket provided on
each side thereof, a pair of gas diffusion layers, an anode
separator, and a cathode separator, wherein the anode separator and
the cathode separator constituting adjacent cells are arranged to
face each other and joined together to be integrated with each
other, the anode separator has a protruding bead seal providing a
seal, and the cathode separator has an arched bulge protruding in
the same direction as the bead seal at a location corresponding to
a location where the bead seal is formed.
7. The fuel cell stack of claim 6, wherein a gasket is provided on
a concave surface of the bulge of the cathode separator at the
location where the bulge is formed, the concave surface being
opposite to a convex surface of the bulge, and a sealing agent is
applied to a convex surface of the bead seal of the anode separator
at the location where the bead seal is formed.
8. The fuel cell stack of claim 7, wherein the bead seal formed at
the anode separator protrudes toward the sub-gasket abutting the
bead seal and is sealed by the sealing agent in tight contact with
the sub-gasket; in a region where hydrogen flows, the anode
separator and the cathode separator are joined together by
junctions at locations on opposite sides of the bead seal; and the
bead seal has a pair of through holes through which the opposite
sides of the bead seal communicate with each other and allowing
hydrogen to flow between the anode separator and the
sub-gasket.
9. The fuel cell stack of claim 7, wherein the bulge formed at the
cathode separator protrudes in a direction opposite to the
sub-gasket abutting the bulge and is sealed by the gasket in tight
contact with the sub-gasket; in a region where air flows, the
cathode separator and the anode separator are spaced apart from
each other at a location outside the bulge around an upstream side
of an air flow path with respect to a direction in which air flows,
while the cathode separator and the anode separator are joined
together by a junction at a location outside the bulge around a
downstream side of the air flow path with respect to the direction
in which air flows; and the cathode separator is holed at the
location outside the bulge around the downstream side of the air
flow path with respect to the direction in which air flows, thus
forming a through hole passing through first and second surfaces of
the cathode separator and allowing air that flows between the
cathode separator and the anode separator to flow between the
cathode separator and the sub-gasket.
10. The fuel cell stack of claim 7, wherein the bulge formed at the
cathode separator protrudes in a direction opposite to the
sub-gasket abutting the bulge and is sealed by the gasket in tight
contact with the sub-gasket, and in a region where air flows, the
gasket has a step such that opposite sides of the gasket
communicate with each other by the step, thus allowing air to flow
between the cathode separator and the sub-gasket.
11. The fuel cell stack of claim 7, wherein the anode separator is
sealed by the sealing agent in tight contact with the sub-gasket,
while the cathode separator is sealed by the gasket in tight
contact with the sub-gasket, and in a region where a coolant flows,
the anode separator and the cathode separator are spaced apart from
each other at locations on opposite sides of the bead seal that is
formed in the region where the coolant flows between the anode
separator and the cathode separator, thus allowing the coolant to
flow between the anode separator and the cathode separator.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims under 35 U.S.C. .sctn. 119(a)
the benefit of Korean Patent Application No. 10-2018-0156386, filed
Dec. 6, 2018, the entire contents of which are incorporated by
reference herein.
BACKGROUND
(a) Technical Field
[0002] The present disclosure relates to a separator assembly for a
fuel cell and a fuel cell stack including the same, more
particularly, to the fuel cell stack configured to provide improved
airtightness and durability while reducing production costs.
(b) Description of the Related Art
[0003] As is well known in the art, a fuel cell is a type of power
generator that converts chemical energy of fuel into electric
energy through an electrochemical reaction in a stack. Fuel cells
have a wide range of applications, including serving as industrial
power generators, serving as household power generators, powering
vehicles, and powering small electronic devices such as portable
devices. In recent years, fuel cells have increasingly been used as
high efficiency clean energy sources.
[0004] FIG. 1 (RELATED ART) is a view showing a configuration of a
typical fuel cell stack, FIG. 2 (RELATED ART) is a view showing a
unit cell for a fuel cell to which a sub-gasket is applied, and
FIG. 3 (RELATED ART) is a view showing an arrangement of gaskets in
the unit cell for the fuel cell to which the sub-gasket is
applied.
[0005] As shown in FIG. 1, a typical fuel cell stack has a membrane
electrode assembly (MEA) 10 located at the innermost portion
thereof. The MEA 10 includes a polymer electrolyte membrane (PEM)
11 allowing transport of positively charged ions (protons)
therethrough, and catalyst layers (CLs), that is, an anode 12 and a
cathode 13, applied on opposite surfaces of the PEM 11 to cause
hydrogen and oxygen to react.
[0006] Further, gas diffusion layers (GDLs) 20 are laminated
outside of the MEA 10 where the anode 12 and the cathode 13 are
located, and separators 30a and 30b each having a flow field for
supplying fuel and discharging water generated by reactions in the
MEA 10 are respectively located outside of the GDLs 20 with gaskets
40 interposed therebetween. End plates 50 are assembled to the
outermost portion of the MEA 10 to structurally support and secure
individual components described above in position.
[0007] Thus, at the anode 12 of the fuel cell stack, an oxidation
reaction in which hydrogen is oxidized takes places to generate
hydrogen ions (protons) and electrons, and the generated protons
and electrons flow to the cathode 13 through the PEM 11 and a wire,
respectively. At the cathode 13, water is generated through an
electrochemical reaction involving the protons and the electrons
that have flowed from the anode 12, and oxygen contained in air,
and this flow of electrons generates electricity.
[0008] Meanwhile, the separators 30a and 30b are generally
manufactured such that lands serving as supports and channels
serving as flow paths of a fluid are alternately repeated.
[0009] In other words, a typical separator has a structure in which
lands and channels (flow paths) are alternately repeated in a
serpentine configuration. Because of this, a channel on one side of
the separator, which faces the GDL 20, is utilized as a space
through which reactant gases such as hydrogen or air flows, while a
channel of the other side is utilized as a space through which a
coolant flows. Accordingly, a single unit cell can be comprised of
a pair of separators, namely one separator with a hydrogen/coolant
channel and the other separator with an air/coolant channel.
[0010] Meanwhile, as shown in FIG. 2, the MEA 10 includes
sub-gaskets 14 surrounding peripheral portions of the anode 12 and
the cathode 13 to facilitate handling of the PEM 11, the anode 12,
and the cathode 13 while improving airtightness of the stack.
[0011] Further, multiple inlet and outlet multiple outlet manifolds
are provided at opposite sides of the sub-gasket 14 and opposite
sides of the separators 30a and 30b, respectively.
[0012] Meanwhile, as shown in FIG. 3, because the reactant gases
and the coolant have to flow between the sub-gasket 14 and the pair
of separators 30a and 30b, injection molded rubber gaskets 40a,
40b, and 40c having a predetermined thickness are arranged between
the sub-gasket 14 and the pair of separators 30a and 30b.
Accordingly, when unit cells are stacked on top of each other, the
gaskets are compressed, thus ensuring airtightness of the stack
while maintaining intervals therebetween.
[0013] However, the rubber gaskets 40a, 40b, and 40c are costly to
manufacture. For this reason, a separator having a bead seal has
been proposed. The bead seal integrally protrudes from the surface
of the separators at a height equal to the thickness of the gaskets
40a, 40b, and 40c arranged between the separators, and a sealing
agent is applied in a thin layer to the separators, thus securing
airtightness of the stack.
[0014] However, in the case of forming a fuel cell stack by
stacking multiple unit cells on top of each other and then
compressing them, the shape of the bead seals is changed due to a
surface pressure acting on portions where the bead seals are
formed, leading to degradation in airtightness of the stack.
[0015] The foregoing is intended merely to aid in the understanding
of the background of the present disclosure, and is not intended to
mean that the present disclosure falls within the purview of the
related art that is already known to those skilled in the art.
SUMMARY
[0016] Accordingly, the present disclosure provides a fuel cell and
a fuel cell stack including the same, wherein the fuel cell stack
is configured to provide improved airtightness and durability while
reducing production costs.
[0017] According to one aspect of the present disclosure, there is
provided a separator assembly for a fuel cell, the separator
assembly including: a first separator having a protruding bead seal
providing a seal; a second separator joined to the first separator
to be integrated therewith and having an arched bulge protruding in
the same direction as the bead seal at a location corresponding to
a location where the bead seal is formed; a gasket provided on a
concave surface of the bulge of the second separator at the
location where the bulge is formed, the concave surface being
opposite to a convex surface of the bulge; and a sealing agent
applied to a convex surface of the bead seal of the first separator
at the location where the bead seal is formed.
[0018] The bulge formed at the second separator may be lower in
protruding height than the bead seal formed at the first
separator.
[0019] A height of the bulge formed at the second separator may be
equal to or less than the sum of thicknesses of the first separator
and the second separator.
[0020] The gasket may be larger in width than the sealing
agent.
[0021] The gasket may be formed by injecting an elastic rubber
material, and the sealing agent may be applied by screen
coating.
[0022] According to another aspect of the present disclosure, there
is provided a fuel cell stack formed by stacking multiple unit
cells, the fuel cell stack including: the multiple unit cells each
comprised of a membrane electrode assembly having a sub-gasket
provided on each side thereof, a pair of gas diffusion layers, an
anode separator, and a cathode separator, wherein the anode
separator and the cathode separator constituting adjacent cells are
arranged to face each other and joined together to be integrated
with each other, the anode separator may have a protruding bead
seal providing a seal, and the cathode separator may have an arched
bulge protruding in the same direction as the bead seal at a
location corresponding to a location where the bead seal is
formed.
[0023] A gasket may be provided on a concave surface of the bulge
of the cathode separator at the location where the bulge is formed,
the concave surface being opposite to a convex surface of the
bulge, and a sealing agent may be applied to a convex surface of
the bead seal of the anode separator at the location where the bead
seal is formed.
[0024] The bead seal formed at the anode separator may protrude
toward the sub-gasket abutting the bead seal and may be sealed by
the sealing agent in tight contact with the sub-gasket; in a region
where hydrogen flows, the anode separator and the cathode separator
may be joined together by junctions at locations on opposite sides
of the bead seal; and the bead seal may have a pair of through
holes through which the opposite sides of the bead seal communicate
with each other and allowing hydrogen to flow between the anode
separator and the sub-gasket.
[0025] The bulge formed at the cathode separator may protrude in a
direction opposite to the sub-gasket abutting the bulge and may be
sealed by the gasket in tight contact with the sub-gasket; in a
region where air flows, the cathode separator and the anode
separator may be spaced apart from each other at a location outside
the bulge around an upstream side of an air flow path with respect
to a direction in which air flows, while the cathode separator and
the anode separator may be joined together by a junction at a
location outside the bulge around a downstream side of the air flow
path with respect to the direction in which air flows; and the
cathode separator may be holed at the location outside the bulge
around the downstream side of the air flow path with respect to the
direction in which air flows, thus forming a through hole passing
through first and second surfaces of the cathode separator and
allowing air that flows between the cathode separator and the anode
separator to flow between the cathode separator and the
sub-gasket.
[0026] The bulge formed at the cathode separator may protrude in a
direction opposite to the sub-gasket abutting the bulge and may be
sealed by the gasket in tight contact with the sub-gasket, and in a
region where air flows, the gasket may have a step such that
opposite sides of the gasket communicate with each other by the
step, thus allowing air to flow between the cathode separator and
the sub-gasket.
[0027] The anode separator may be sealed by the sealing agent in
tight contact with the sub-gasket, while the cathode separator may
be sealed by the gasket in tight contact with the sub-gasket, and
in a region where a coolant flows, the anode separator and the
cathode separator may be spaced apart from each other at locations
on opposite sides of the bead seal that is formed in the region
where the coolant flows between the anode separator and the cathode
separator, thus allowing the coolant to flow between the anode
separator and the cathode separator.
[0028] According to the present disclosure, when a pair of
separators are joined together to be integrated with each other,
the bead seal is applied to one separator while the arched bulge
and the rubber gasket are applied to the other separator, whereby
it is possible for the stack to be improved in airtightness and
durability while reducing production cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and other objectives, features and other
advantages of the present disclosure will be more clearly
understood from the following detailed description when taken in
conjunction with the accompanying drawings, in which:
[0030] FIG. 1 (RELATED ART) is a view showing a configuration of a
typical fuel cell stack;
[0031] FIG. 2 (RELATED ART) is a view showing a unit cell for a
fuel cell to which a sub-gasket is applied;
[0032] FIG. 3 (RELATED ART) is a view showing an arrangement of
gaskets in the unit cell for the fuel cell to which the sub-gasket
is applied;
[0033] FIGS. 4 and 5 are views showing a main part of a separator
assembly for a fuel cell according to an embodiment of the present
disclosure;
[0034] FIG. 6 is a view showing a region where hydrogen flows in
the separator assembly for the fuel cell according to the
embodiment of the present disclosure;
[0035] FIGS. 7 and 8 are views showing a region where air flows in
the separator assembly for the fuel cell according to the
embodiment of the present disclosure;
[0036] FIG. 9 is a view showing a region where a coolant flows in
the separator assembly for the fuel cell according to the
embodiment of the present disclosure; and
[0037] FIG. 10 is a view showing a surface pressure acting on the
separator assembly for the fuel cell according to the embodiment of
the present disclosure.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0038] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g. fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example both
gasoline-powered and electric-powered vehicles.
[0039] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a," "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items. Throughout the
specification, unless explicitly described to the contrary, the
word "comprise" and variations such as "comprises" or "comprising"
will be understood to imply the inclusion of stated elements but
not the exclusion of any other elements. In addition, the terms
"unit", "-er", "-or", and "module" described in the specification
mean units for processing at least one function and operation, and
can be implemented by hardware components or software components
and combinations thereof.
[0040] Further, the control logic of the present disclosure may be
embodied as non-transitory computer readable media on a computer
readable medium containing executable program instructions executed
by a processor, controller or the like. Examples of computer
readable media include, but are not limited to, ROM, RAM, compact
disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart
cards and optical data storage devices. The computer readable
medium can also be distributed in network coupled computer systems
so that the computer readable media is stored and executed in a
distributed fashion, e.g., by a telematics server or a Controller
Area Network (CAN).
[0041] Hereinbelow, exemplary embodiments of the present disclosure
will be described in detail with reference to the accompanying
drawings. The exemplary embodiments of the present disclosure are
presented to make complete disclosure of the present disclosure and
help those who are ordinarily skilled in the art best understand
the disclosure. Various changes to the following embodiments are
possible and the scope of the present disclosure is not limited to
the following embodiments. Throughout the drawings, the same
reference numerals will refer to the same or like parts.
[0042] A fuel cell stack according to an embodiment of the present
disclosure is proposed to improve a shape and an airtight structure
of a separator while maintaining a stack structure according to the
related art shown in FIGS. 1 and 2, thus improving airtightness
while securing fluidity of reactant gases and a coolant. Thus, as
shown in FIGS. 1 and 2, the fuel cell stack according to the
embodiment of the present disclosure is comprised of multiple unit
cells stacked on top of each other in series. Each of the unit
cells has a membrane electrode assembly (MEA) 10 having a
sub-gasket 14 provided on each side thereof, a pair of gas
diffusion layers (GDLs) 20, and anode and cathode separators 30a
and 30b. Accordingly, an anode separator 30a constituting one cell
and a cathode separator 30b constituting an adjacent cell are
arranged to face each other. In the present embodiment, the anode
separator 30a and the cathode separator 30b facing each other are
joined together to be integrated with each other, thus forming a
separator assembly.
[0043] FIGS. 4 and 5 are views showing a main part of the separator
assembly for the fuel cell according to the embodiment of the
present disclosure. For example, FIGS. 4 and 5 show the shape and
the airtight structure of the separator, which are improved in the
present embodiment. Herein, for convenience of explanation, the
sub-gasket 14, an anode separator 200, and a cathode separator 100
are shown in a state of being spaced apart from each other.
[0044] As shown in FIG. 5, the separator assembly for the fuel cell
according to the present embodiment is proposed to minimize
deformation of the separators due to a surface pressure while
maintaining airtightness in a case where separator assemblies are
stacked on top of each other and compressed, and preferably
includes: a first separator 200 having a protruding bead seal 210
providing a seal; a second separator 100 joined to the first
separator 200 to be integrated therewith and having an arched bulge
110 protruding in the same direction as the bead seal 210 at a
location corresponding to a location where the bead seal 210 is
formed; a gasket 300 provided on a concave surface of the bulge 110
of the second separator 100 at the location where the bulge 110 is
formed, the concave surface being opposite to a convex surface of
the bulge 110; and a sealing agent 400 applied to a convex surface
of the bead seal 210 of the first separator 200 at the location
where the bead seal 210 is formed. Hereinafter, the first separator
200 will be described as the anode separator, and the second
separator 100 will be described as the cathode separator.
[0045] Further, it is preferable that the gasket 300 is formed by
injecting an elastic rubber material, and the sealing agent 400 is
applied by screen coating.
[0046] The bulge 110 corresponding to the bead seal 210 provided at
the anode separator 200 is provided at the cathode separator 100 as
described above. This is to prevent a case in which when stacking
the fuel cell stack, if a surface pressure acts on a portion where
the bead seal 210 is formed, the cathode separator 10 is deformed
into a space defined by the bead seal 210 between the cathode
separator 100 and the anode separator 200, causing a reduction in
contact force between the cathode separator 100 and the anode
separator 200 and airtightness of the stack.
[0047] To this end, in the present embodiment, the arched bulge 110
is pre-formed at the cathode separator 100 such that even if the
surface pressure is generated on the portion where the bead seal
210 is formed, an arched structure prevents the portion from
undergoing deformation.
[0048] Accordingly, it is preferable that the bulge 110 formed at
the cathode separator 100 is lower in protruding height than the
bead seal 210 formed at the anode separator 200. It is more
preferable that a height h of the bulge 110 is equal to or less
than the sum of thicknesses of the anode separator 200 and the
cathode separator 100. Further, it is preferable that a width
W.sub.G of the gasket 300 is larger than a width W.sub.S of the
sealing agent 400 in order to disperse the surface pressure. It is
more preferable that the width W.sub.G of the gasket 300 is larger
than the sum of the width W.sub.S of the sealing agent 400 and a
stacking tolerance. If the width W.sub.S of the sealing agent 400
is larger than the width W.sub.G of the gasket 300, the width of
the bead seal 210 is increased accordingly. In this case, the bead
seal 210 is weak in rigidity. Thus, when stacking the fuel cell
stack, the bead seal 210 may undergo deformation, leading to
degradation in airtightness.
[0049] Meanwhile, it is preferable that the airtight structure
proposed above is applied to a region surrounding the MEA
constituting the fuel cell stack and regions surrounding multiple
inlet manifolds and multiple outlet manifolds, thus securing
airtightness of such regions.
[0050] However, a flow path for flowing of reactant gases such as
hydrogen and air and the coolant has to be secured between a
reaction surface on which the MEA is located, the inlet manifolds,
and the outlet manifolds.
[0051] Thus, the separator assembly according to the present
disclosure can change the structure of any one of the bead seal,
the bulge, and the gasket such that a flow path is formed in each
region where hydrogen, air, or the coolant flows.
[0052] FIG. 6 is a view showing a region where hydrogen flows in
the separator assembly for the fuel cell according to the
embodiment of the present disclosure, FIGS. 7 and 8 are views
showing a region where air flows in the separator assembly for the
fuel cell according to the embodiment of the present disclosure;
FIG. 9 is a view showing a region where a coolant flows in the
separator assembly for the fuel cell according to the embodiment of
the present disclosure. For example, FIG. 6 corresponds to a
sectional structure taken along line A-A of FIG. 2, FIGS. 7 and 8
correspond to a sectional structure taken along line C-C of FIG. 2,
and FIG. 9 corresponds to a sectional structure taken along line
B-B of FIG. 2.
[0053] First, in the region where hydrogen flows as shown in FIG.
6, the bead seal 210 formed at the anode separator 200 protrudes
toward the sub-gasket 14 abutting the bead seal and is sealed by
the sealing agent 400 in tight contact with the sub-gasket 14.
Herein, the anode separator 200 and the cathode separator 100 are
joined together by junctions W1 and W2 at locations on opposite
sides of the bead seal 210.
[0054] Further, the bead seal 210 has a pair of communication holes
211 through which the opposite sides of the bead seal 210
communicate with each other. Thus, hydrogen flows between the anode
separator 200 and the sub-gasket 14 through the pair of
communication holes 211 whereby hydrogen is supplied to the
reaction surface.
[0055] Further, in the region where air flows as shown in FIG. 7,
the bulge 110 formed at the cathode separator 100 protrudes in a
direction opposite to the sub-gasket 14 abutting the bulge and is
sealed by the gasket 300 in tight contact with the sub-gasket 14.
Herein, the cathode separator 100 and the anode separator 200 are
spaced apart from each other at a location outside the bulge 110
around the upstream side of an air flow path with respect to a
direction in which air flows, while the cathode separator 100 and
the anode separator 200 are joined together by the junction W1 at a
location outside the bulge 110 around the downstream side of the
air flow path with respect to the direction in which air flows.
[0056] Further, the cathode separator 100 is holed at the location
outside the bulge 110 around the downstream side of the air flow
path with respect to the direction in which air flows, thus forming
a through hole 111 passing through first and second surfaces of the
cathode separator and allowing air that flows between the cathode
separator 100 and the anode separator 200 to flow between the
cathode separator 100 and the sub-gasket 14. Thus, air flows
between the cathode separator 100 and the anode separator 200 and
then passes through the through hole 111 at the location outside
the bulge 110 around the upstream side of the air flow path with
respect to the direction in which air flows. Thereafter, air flows
between the cathode separator 100 and the sub-gasket 14 at the
location outside the bulge 110 around the downstream side of the
air flow path with respect to the direction in which air flows,
whereby air is supplied to the reaction surface.
[0057] Meanwhile, FIG. 8 shows another embodiment of air flow in
the region where air flows. The bulge 110 formed at the cathode
separator 100 protrudes in the direction opposite to the sub-gasket
14 abutting the bulge and is sealed by the gasket 300 in tight
contact with the sub-gasket 14. Further, the anode separator 200
and the cathode separator 100 are joined together by the junctions
W1 and W2 at locations on the opposite sides of the bead seal
210.
[0058] Herein, the gasket 300 provided between the cathode
separator 100 and the sub-gasket 14 has a step 310 such that
opposite sides of the gasket 300 communicate with each other by the
step 310. Thus, air is allowed to flow between the cathode
separator 100 and the sub-gasket 14, whereby air is supplied to the
reaction surface.
[0059] Meanwhile, in the region where the coolant flows as shown in
FIG. 9, the anode separator 200 is sealed by the sealing agent 400
in tight contact with the sub-gasket 14, while the cathode
separator 100 is sealed by the gasket 300 in tight contact with the
sub-gasket 14.
[0060] Herein, the anode separator 200 and the cathode separator
100 are spaced apart from each other at locations on the opposite
sides of the bead seal 210 that is formed in the region where the
coolant flows. Thus, the coolant is allowed to flow between the
anode separator 200 and the cathode separator 100.
[0061] Meanwhile, FIG. 10 is a view showing the surface pressure
acting on the separator assembly for the fuel cell according to the
embodiment of the present disclosure. When stacking the fuel cell
stack by employing the separator assembly according to the present
disclosure, it was found that surface pressure distribution A shows
a tendency in surface pressure to increase toward the center of the
bead seal 210 depending on the shape of the bead seal 210. Hence,
to prevent the cathode separator 100 from being deformed due to the
surface pressure formed as described above, the arched bulge 110
formed at the cathode separator 100 is employed.
[0062] Although the exemplary embodiments of the present disclosure
has been described for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the disclosure as disclosed in the accompanying
claims.
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